So have I understood it correctly that you can fill all 12 memory slots on the SR-2 with memory and as long as the memory is dual ranked it will run at 1333MHz without overclocking?

EX3CUT1ON
So have I understood it correctly that you can fill all 12 memory slots on the SR-2 with memory and as long as the memory is dual ranked it will run at 1333MHz without overclocking?

Sorry to say it but you've misunderstood. Each processor has 3 memory channels. The highest-end Xeons are used in all the examples, and they support the memory speeds 800, 1066 and 1333 MHz without overclocking. If you put in 6 sticks (3 per processor, 1 per channel), each stick will operate at 1333 MHz. If you put in 12 sticks (6 per processor, 2 per channel) then the processor will lower the RAM multiplier, operating your 1333 MHz-capable RAM at 1066 MHz instead.

That's it for the memory rate part of your question.

As for how to utilize 100% of the memory bandwidth that 1333 MHz offers, read the part of the first post that says "Now, if we want 1333 MHz bandwidth out of all sticks, we have two options:", which expains your options when it comes to squeezing all the juice out of the memory bus and getting the most bandwidth out of your RAM. It can be done in two ways; by choosing between either 6x dual ranked and no overclocking, or 12x single ranked and overclocking the base clock from 133 to 166 MHz (which not only speeds up your RAM again, but makes your processor 25% faster). Either choice will give you the desired result (1333 MHz rate and utilizing the entire available memory bandwidth for each processor, giving you the best memory transfer speeds). For further details, re-read the first post, hopefully it became clearer now. :-) I'd go with option #2, 12 single-ranked sticks and overclocking, since it gives you the best CPU performance. When overclocking, it's beneficial to populate all slots since the lowered RAM multiplier helps you overclock everything without clocking the RAM higher than it can handle. For instance, at just 3 sticks per processor and a 133 -> 166 BCLK overclock, you will take your 1333 MHz RAM to ~1660 MHz, which may damage it or at least be very unstable since the memory chips won't be rated for a timing that high, that's why 12x single ranked is the best for this overclocking example, as filling each slot lowers the RAM multiplier letting us overclock the CPU further without taking the RAM out of spec. You mentioned in another thread that you're new to building computers, so please excuse me if this isn't clear enough. 

nullack 
Thanks again for the info mate :) 


With raising the bclk its my understanding the uncore clock, qpi clock and memory clock all raise. So, an oc with two 5630s should bring it back into line with 1333mhz and the 6.4 qpi rate, all at stockish clocks except for the bclk. 

Anyway, some sacrifice on mem speed isnt much of a compromise for getting two physical cores and four logical cores extra for the same cost as on X5650 :) 

 

Yeah, pretty much all clocks in the system derive from the bus/base clock, which is 133 MHz. The SR-2 lets us overclock this, which will raise everything that derives from it (such as RAM and CPUs). Uncore is locked to a 20x multiplier on all Westmeres (at least that's the multiplier that the highest end models use; lower end models may use a lower uncore multiplier). For anyone wondering, Uncore is basically the clock for everything inside the CPU that isn't a core. It's logical that QPI would go up too since it has to derive from either the CPU or bus clocks.


Indeed, it'd be fun to see if there are any benchmarks comparing the "e" economy and "x" models.

BigBrother

EX3CUT1ON
So have I understood it correctly that you can fill all 12 memory slots on the SR-2 with memory and as long as the memory is dual ranked it will run at 1333MHz without overclocking?

Sorry to say it but you've misunderstood. Each processor has 3 memory channels. The highest-end Xeons are used in all the examples, and they support the memory speeds 800, 1066 and 1333 MHz without overclocking. If you put in 6 sticks (3 per processor, 1 per channel), each stick will operate at 1333 MHz. If you put in 12 sticks (6 per processor, 2 per channel) then the processor will lower the RAM multiplier, operating your 1333 MHz-capable RAM at 1066 MHz instead.

That's it for the memory rate part of your question.

As for how to utilize 100% of the memory bandwidth that 1333 MHz offers, read the part of the first post that says "Now, if we want 1333 MHz bandwidth out of all sticks, we have two options:", which expains your options when it comes to squeezing all the juice out of the memory bus and getting the most bandwidth out of your RAM. It can be done in two ways; by choosing between either 6x dual ranked and no overclocking, or 12x single ranked and overclocking the base clock from 133 to 166 MHz (which not only speeds up your RAM again, but makes your processor 25% faster). Either choice will give you the desired result (1333 MHz rate and utilizing the entire available memory bandwidth for each processor, giving you the best memory transfer speeds). For further details, re-read the first post, hopefully it became clearer now. :-) I'd go with option #2, 12 single-ranked sticks and overclocking, since it gives you the best CPU performance. When overclocking, it's beneficial to populate all slots since the lowered RAM multiplier helps you overclock everything without clocking the RAM higher than it can handle. For instance, at just 3 sticks per processor and a 133 -> 166 BCLK overclock, you will take your 1333 MHz RAM to ~1660 MHz, which may damage it or at least be very unstable since the memory chips won't be rated for a timing that high, that's why 12x single ranked is the best for this overclocking example, as filling each slot lowers the RAM multiplier letting us overclock the CPU further without taking the RAM out of spec. You mentioned in another thread that you're new to building computers, so please excuse me if this isn't clear enough. 

 
What if I'm using 12 sticks of dual ranked memory apose to single ranked will I still be able to overclock the baseclock the same since I want to get some Corsair Dominator GT memory which is only dual ranked?

BigBrother

EX3CUT1ON  
What if I'm using 12 sticks of dual ranked memory apose to single ranked will I still be able to overclock the baseclock the same since I want to get some Corsair Dominator GT memory which is only dual ranked?

If you use 12 sticks of dual-ranked memory, the following will happen:

Your RAM multiplier will lower, taking the 1333 MHz RAM to 1066 MHz. If you were to leave it like this, you would be able to utilize 92% of the maximum memory bandwidth capacity of the Xeons (1% more than 2x single-ranked per channel at 1066 MHz).

Next, do the 133 -> 166 MHz BCLK overclock, which takes your 1066 MHz sticks back up to ~1330 MHz. Now, your memory will be capable of feeding the CPU 102% of its maximum memory bandwidth capacity (3% more than 2x overclocked single-ranked per channel).

Of course, the CPU can't make use of 102%. It'll run at 100%.

The difference between 12x single-ranked at 99% or 12x dual-ranked at 100% is pretty much unmeasurable.
When going for 12 sticks and overclocking, get whichever is cheapest (single or dual ranked) of the memory brand and capacity that you want. :-) Latency will be a tiny bit higher with 2x dual-ranked sticks due to the switching between 4 memory chip banks (2 per DIMM), but the extra bandwidth that this provides makes up for it. With 2x single-ranked sticks per channel, the CPU only has to switch between 2 memory chip banks (1 per DIMM). It's negligible, so just get whichever is cheapest.

Thanks again BigBrrother.

Here's an Intel 5600 series datasheet with some good info about the memory controller's features beginning on page 57:

http://www.intel.com/Assets/PDF/datasheet/323370.pdf

Hi, I know it's been very long time since the last post however I think this subject can't get old :) I have been reading this thread with an intrest however last post actually ruined my understanding...
 
leakyboat populated each slot on SR-2 with 4GB sticks and used default configuration in BIOS and the memory multiplayer didn't seem to drop as stated previously in the thread. With all slots populated it should be running at 1066 as mentioned before at default. Does it mean that leakybot overclocked his CPU like from 133 to 166 to achieve 1333 on all sticks?
 
I have recently ordered SR-2 and I am looking for some nice memory. I need 48gb ideally ECC and I want to overclock my future X5650 at least 25% or more... After reading this thread I thought I need 12 sticks 4 GB each (dual or single ranked whatever is cheapest) 1333Mhz ECC then my mem multi should go down so I will be able to overclock CPU and get my memory back at 1333. And if I want to overclock even more I should get 1600.
 
But from leakyboat's post I can see that populating 12 slots with 1333 didn't drop the mem multi so does it mean that I won't be able to overclock my CPU with this memory?
 
I would be grateful for any clarification as I am a bit lost.
 
Thanks!
 
 

 

Thank you KONAn, I got it.

Ok, so then would populating half the slots with 8gb sticks work using two 5650s?

The board can actually handle 384 Gig's of ram, 32 GB Dimms, which are now appearing on the market. This is generally not advisable because of the issues listed earlier in the thread. And any amount above 24 gig's ram max will have the effect of surpassing the bandwidth. The only times this should even be considered is if the board is to be used solely for applications like, Server Environment, Engineering drafting, Drafting in general. Music or Video Editing. These types of  goals it can be feasible to go for a larger amount of ram. Because the Ram that will be used by the system on average will far surpass the average user, or gamers needs.

i must say i should rise my hand ty you that took care of a few ram ? i had no need to post you just answered all 3 of them..

I would like to note that BigBrother's claim about the 2 memory sticks is true for the 5500 series xeons as indicated on pages 125-130 for the 5500 series volume 2 data sheet which states that for population of 2 sticks per channel will downclock ram to 1066, but 1 channel can run at 1333. This is NOT true for the 5600 series which he has indicated in this entire post.
 
It is indicated on pages 57-60 of volume 2 of the data sheet for the 5600 series xeons that having 2 sticks of registered dimms per channel or 2 unbuffered (ECC or non-ECC) will run at 1333. This claim and proof is against what BigBrother has stated. I suggest for future purposes that these articles be reviewed for accuracy, as the original poster was totally incorrect about all of this.

 Hello there, I am dearly sorry for bothering you with this but for this overclocking technique to work when filling all twelve slots, will two of this particular ram set work? Additionally I have been unable to find out if it is double or single rank. 

CORSAIR Vengeance 24GB (6 x 4GB) 240-Pin DDR3 SDRAM DDR3 1600 Desktop Memory Model CMZ24GX3M6A1600C9

 One last thing that is of minor importance and I apologise if this is not the right place to be asking this (my first post). For the SR2 build I am making, the case I intend to use: the mountain mods u2-ufo will have space for 12 120mm fans, two of which I intend to fill with the Corsair H80 liquid closed circuit water cooler but from what I understand the SR2 has only eight fan headers. Since I have never worked with a motherboard of this magnitude before I am unaware as to if two of the eight fan headers are dedicated to the CPU fans themselves,  are there three or four pins per header, and if using two to four cable splitters (depending whether I have eight or six fan headers to work with) to plug two fans per header will put too much stress on the mother board?
 
To sum it all up, will using cable splitters to get ten 120mm fans plus two Corsair H80 CPU coolers to work with eight fan headers put too much stress on the motherboard and are two of those headers reserved for the CPU fans/coolers or do the fans have their own connectors (The two H80s in my case) leaving me with eight headers for ten fans ? And are the fan headers three or four pins.
 
 Sorry for the convoluted and ignorant question, if necessary ask me to reiterate my question(s) if they/it do not make sense.
 
 Thankyou.

Heya
 
Sory for ''steal'' the topic - just got lil question will 6x4gb/ 2x 3 triple channel ECC REG Kingston quad Rank(rank matters?) work with 2xe5530?
 
 
Also I will populate 6 slots of ram, leaving 6 slots empty. If I buy 2x 3 stick 6x 8gb memory and add it to my existing 24 gb (topping up 72 gb) will this work or they all have to be 8 gb ? 
 
both rams are exactly that same - only capacity changes.
Thanks/